With regard to an electric motor control device including a multiple of current detecting means, there is a demand to continue drive of an electric motor even when one portion of the current detecting means fails, and technology that identifies the failed current detecting means is needed in order to realize this demand. Also, when a failure location is known, maintenance such as replacement and repair becomes easier.
To date, as this kind of electric motor control device, there is an electric motor control device such that a failure diagnosis current command value is input into a current controller of the electric motor control device, and whether or not current detecting means has failed is determined from a voltage command value generated in the current controller, as disclosed in, for example, JP-A-2007-082313 (Patent Document 1).